Burglar-alarm



(No Mudel.)

W. E. MCINTOSH.

BURGLAR ALARM;

Patented May 3. 11888, I

UNITED STATES PATENT OFFICE. v I

IVILLIAM E. MOINTOSH, OF KEENE, NEW HAMPSHIRE.

BURGLAR ALARML.

SPECIFICATION forming part of Letters Patent No.382,481-,dated ma8,1888.

Application filed March 93, 1888. Serial No. 268,210. (No model) To allwhom it may concern.-

Be it known that I, WILLIAM E. MoINTosII, a citizen of the UnitedStates, residing at Keene, in the county of Cheshire and State of New.Hampshire,have invented certain new and usefulImprovementsinBurglar-Alarms; and I do hereby declare the following tobe a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it my improvements. Fig. 2 isa vertical section taken on line as w of Fig. 1.

In my improved construction the casing or body A has chamber B in itsupper part, said chamber having a concave floor, the lowest part ofwhich is on a central line running from front to rear. A slot, a, ismade in the central part of said floor, for the purpose hereinafterstated. A roller, E, is placed in chamber B, said roller being loose andresting on the floor at the center and over slot at, when the device isset and held in a perpendicular position.

Below the chamber B is placed the alarm mechanism. A shaft, b, which ismounted in suitable bearings, carries a striking-hammer,

0, which extends forward, so that it isin po sition to strike the bellD, which is held by an arm, 0, in front of the mechanism. The rod ofsaid hammer is provided with a projection or short vertical arm, a,which is in position under the slot at to enter the said slot when thehammer is raised in making its upward stroke. On the said shaft b isalso placed a pallet, d, which engages with an escape wheel, e, thelatter being on ashaft which carries a pinion or cage wheel, f. Y

0 indicates the winding-shalt, which is pro-. vided with a handle-knob,i, for winding up the device. On said shaft 0 is placed the mainspringF, which actuates the alarm mechanism, one end of said spring beingsecured to a cross bar in the rear.

A gear-wheel, g, is placed loose on the winding-shaft C, so that whenshaft G is turned in winding up the device'the wheel 9 is not rotated;but whenthe said shaft is actuated by the spring F a springpawl, h,attached to wheel 9, engages with the ratchet-wheel m, fixed on thewinding-shaft, and wheel is thus caused to rotate, and, engaging withwheel f, imparts motion to the pallet and hammer, the latter repeatedlystriking the bell and sounding an alarm. i v

On the inner end of ,thewinding-shaft is a wheel, 'n, provided with asmall arm which engages with the teethof a wheel, 10, below, these partsforming a governing device which limits the rotation of said'shaft.

By my improvement, as above described, the device is rendered moresimple in construction, moredurable, and cheaper in manufacture. It alsohas greater power and in operation produces a louder sound.

In an alarm device, a chamber provided with a curved floor which isslotted at the center,

and a loose roller in said chamber, in combination with an alarmmechanism having a bell and provided with a striking-hammer, which isprovided with an arm or projection in position to enter the slot in thefloor when the hammer makes its upward n1ovenient,'substantially as andfor thepurposes described.

In testimony whereof I have affixed my signaturein presence of twowitnesses. 7

WILLIAM E. MoINTosH.

Witnesses:

FRANK H. WYMAN, JEROME E. WRIGHT.

